Defense Secretary Chuck Hagel has directed all of the services to review their hairstyle policies in response to a letter from the Congressional Black Caucus.

The lawmakers wrote to Hagel on April 10 in response to an online controversy sparked by the Army’s new grooming regulation.

The revised Army Regulation 670-1, published March 31, bans most twists, dreadlocks and large cornrows — styles predominantly worn by African-American women. Though it’s meant to help make soldiers’ appearances consistent, some black military women have criticized the update as racially biased.

“I want to assure you that, while none of the Army’s revised grooming and appearance policies were designed or intended to discriminate or disparage against any service members, I take your concerns very seriously,” Hagel wrote in his response, sent Tuesday.

Hagel also directed the service secretaries and military chiefs to review their respective policies, specifically:

■ Each service will review the definitions of authorized and prohibited hairstyles contained in each of their policies and revise any offensive language within the next 30 days.

■ During the next three months, each service will review its hairstyle policy “as they pertain to African American women to ensure standards are fair and respectful of our diverse force, while also meeting our military services’ requirements,” Hagel said.

The results from these reviews will be submitted to Hagel for potential “appropriate adjustments” to Defense Department policy, he wrote.

In a statement, Rep. Marcia Fudge, the chairwoman of the Congressional Black Caucus, thanked Hagel for his “thoughtful” response.

“Secretary Hagel has committed to careful review of each service’s language and grooming policies to ensure both are clear of offensive language and are respectful of the diversity within our armed forces,” Fudge said. “Members of the CBC appreciate Secretary Hagel for his prompt response to our letter and for seriously considering our concerns.”

In their original letter to Hagel, the women members of the Congressional Black Caucus wrote: “Though we understand the intent of the updated regulation is to ensure uniformity in our military, it is seen as discriminatory rules targeting soldiers who are women of color with little regard to what is needed to maintain their natural hair.”

They also said that while Army officials have said the regulation applies to all soldiers, regardless of race, references in the rule calling hairstyles worn mostly by black women “unkempt” and “matted” are offensive and show a lack of “cultural sensitivity.”